I have both on hand, I set up my 20" with a 25t/9t but I have been seeing a lot of folks running 28t/9t. Is there that big of a difference in feels when you ride and doing trick?
i run 28/9, used to run 25/9 but prefer the stiffer gearing. only tricks that really make a difference are cab tricks because of the pedal pressure, easy to get used too though.
i find it makes fakies easier on cassettes, for some reason when i switched from 25-9 to 28-9 back in the day i just found the backpedal timing to be way easier. it can make getting a lot of speed in short run ups harder if you dont have the leg power though.